Former Secretary of State Colin Powell, a retired general and long-serving Republican, has gone into hiding after he detonated his surprise endorsement of President Barack Obama, whose national security policies have contradicted Powell’s most prominent contributions to public policy.

“Powell has been on the road traveling all week,” his secretary wrote in response to an interview request by The Daily Caller.

“In any event, he said what he had to say and does not plan to do any further interviews regarding the election,” she added.

Powell’s late hit was a surprise that gave Team Obama footage for a new ad that ran in 10 swing states starting Nov. 1.

“I voted for him in 2008, and I plan to stick with him in 2012, and I’ll be voting for he and for Vice President Joe Biden next month,” Powell says in the CBS clip in the ad.

“I didn’t give anybody an early notice” of the endorsement, Powell told CBS. However, he added, “I speak to the president on a regular basis.”

The endorsement was razzed by John Sununu, a leading surrogate for Gov. Mitt Romney.

“When you take a look at Colin Powell, you have to wonder whether that’s an endorsement based on issues or whether he’s got a slightly different reason for preferring President Obama … [which is], I think, when you have somebody of your own race that you’re proud of being president of the United States,” he said.

Powell’s endorsement came as a surprise to many pundits because President Obama’s policies have differed substantially from those Powell once advocated.

The so-called “Powell doctrine,” for example, urged the massive use of force to produce rapid and decisive results.

Obama has not followed that policy during his intervention in the Libyan wars, even after the U.S. Embassy in Benghazi was assaulted and destroyed Sept. 11.

In fact, Obama did not even deploy more than a handful of ground forces, ensuring the new Libyan government was exposed to threats by Islamist groups like the one that assaulted the embassy.